Nonwoven material and method of making the same

ABSTRACT

A NONWOVEN MATERIAL COMPRISING A LAMINATE HAVING A LAYER OF ADHESIVE AND A MULTIPLICITY OF ELEMENTS LOOPED OUTWARDLY FROM THE LAYER, A BARRIER LAYER SECURED TO THE ADHESIVE LAYER AND MEANS ASSOCIATED WITH THE BARRIER LAYER FOR SECURING THE MATERIAL TO A SURFACE; AND A METHOD OF MAKING BY FIRST EMBEDDING A WEB OF ELEMENTS IN AN OPEN PATTERN OF ADHESIVE BONDING THE ELEMENTS IN THE ADHESIVE, CONSOLIDATING THE ADHESIVE, INTO A CONTINUOUS BACKING LAYER WHILE LOOPING THE ELEMENTS OUTWARDLY FROM THE ADHESIVE BACKING, LAMINATING A BARRIER LAYER TO THE ADHESIVE BACKING AND APPLYING A MEANS ASSOCIATED WITH THE BARRIER LAYER FOR SECURING THE FABRIC TO A SURFACE. IN CERTAIN INSTANCES A SECOND PATTERN OF ADHESIVE MAY BE APPLIED TO THE FIRST PATTERN OF THE ADHESIVE PRIOR TO THE CONSOLIDATION STEP.

Stpf. 5, 1972 H, L, splGELBERG ETAL 3,689,353

NONWOVEN MATERIAL AND METHOD OF MAKING THE SAME Filed Oct. 5. 1970 5Sheets-Sheet 1 MSQ ' Sept. 5, 1972 H. L, sPlGELBi-:RG ET AL 3,689,353

NONWOVEN MATERIAL AND METHOD OF MAKING THE SAME Filed Oct. 5. 1970 5Sheets-Sheet 2 Sept. 5, 1972 H, SP|GELBERG ET AL 3,689,353

NONWOVEN MATERIAL AND METHOD OF MAKING THE SAME Filed Oct. 5. 1970 5SheebSSheel', 5

Sept. 5, .1972 H. 1 .sPlGELBERG ET AL 3,689,353

' NONWOVN MATERIAL AND METHOD OI MAKING THE SAME Sept. 5, 1972 l H. L.SPIGELBERG ET AL NONWOVEN MATERIAL AND METHOD OF MAKING THE SAME FiledOct. 5. 1970 5 Sheets-Sheet 5 v -T-gJj Mfr/6K Pfff/@v Patented Sept. 5,1972 U.S. Cl. 161--63 30 Claims ABSTRACT OF THE DISCLOSURE A nonwovenmaterial comprising a laminate having a layer of adhesive and amultiplicity of elements looped outwardly from the layer, a barrierlayer secured to the adhesive layer and means associated with thebarrier layer for securing the material to a surface; and a method ofmaking the material by first embedding a web of elements in an openpattern of adhesive bonding the elements in the adhesive, consolidatingthe adhesive, into a continuous backing layer while looping the elementsout wardly from the adhesive backing, laminating a barrier layer to theadhesive backing and applying a means associated with the barrier layerfor securing the fabric to a surface. In certain instances a secondpattern of adhesive may be applied to the rst pattern of the adhesiveprior to the consolidation step.

RELATED APPLICATIONS George H. Saunders, Robert C. Sokolowski and RobertJ. Stumpf, Ser. No. 498,929, filed Oct. 20, 1965, now abandoned andreplaced by Ser. No. 79,287, filed Oct. 8, 1970.

Ronald H. Wideman, Ser. No. 551,605, filed May 20, 1966 and now U.S.Pat. No. 3,553,064.

Robert J. Stumpf and William L. Mowers, Ser. No. 533,483, filed May 27,1966 and now U.S. Pat. No. 3,553,065.

Robert J. Stumpf, Ser. No. 769,959, filed Oct. 23, 1968, now abandonedand replaced by Robert I. Stumpf, Ser. No. 31,225, filed Apr. 23, 1970.19lobert J. Stumpf, Ser. No. 820,224, filed Apr. 29,

Herman G. Minshell, Robert J. Stumpf and William I.

Mattes, Ser. No. 77,840, filed Oct. 5, 1970.

DESCRIPTION OF THE INVENTION The present invention relates in general tononwoven fabrics and, more particularly, to nonwoven wall coveringfabrics and to methods for making high-loft, nonwoven wall coveringfabrics.

In recent years, many different types of nonwoven materials have beenproduced, both to replace conventional woven fabrics and, also, tocreate new markets in which woven fabrics have not yet becomeestablished. This is particularly true in the case of materials forsingleuse and disposable products, such as: sanitary supplies, hospitalgarments, disposable sheets, and the like. For these applications thenonwoven fabric is generally made in continuous sheet form with one ormore layers of staple length fibers and/or a reinforcing scrim structureadhesively bonded together or laminated between plies of other materialsuch as cellulosic wadding and plastic sheeting. The fibers may benatural, synthetic or various blends and, of course, the particularcomposition of the nonwoven fabric is greatly iniiuenced by its intendeduse.

Exemplary of such nonwoven fabrics are those disclosed in U.S. Pats.Nos. 2,902,395; 3,047,444; 3,072,511; 3,327,708; 3,484,330; 3,553,064and 3,553,065, and the aforesaid copending United States patentapplication, Ser. No. 79,287, which is assigned to the same assignee asthe present application. While the products disclosed in the foregoingissued patents and copending applications have many different attributesand characteristics, they all have one thing in common-viz., theprincipal fibers are nearly all disposed substantially parallel to thesurfaces of the nonwoven material. As a result, the material is eitherrelatively thin and fiat or, such substantial thickness and surfacetexture as are imparted to the fabric are provided by creping orembossing various layers of the material or, in some instances, thefinal nonwoven fabric.

It is also well-known that natural fibers, particularly cotton and wool,have an inherent kink or crimp resulting from the way in which thesefibers grow. This natural crimp is, of course, highly beneficial andcontributes largely to the strength of thread made of a multiplicity ofstaple length fibers. In addition, it is the natural crimp of thesefibers that impart certain characteristics of texture and body materialswoven therefrom.

In contrast, synthetic fibers, as initially formed, do not have anyappreciable kink or crimp since they are generally formed in continuousmonofilaments. However, it is also well-known that most synthetic fiberscan be crimped and heat-set by passing the lfibers through a heatedstuffing box.

Wall covering materials have been produced for years that have a bulky,thick napped construction and appearance. In some instances, types ofcarpeting have been used to cover walls of offices and homes, forexample. Such heavy, substantial appearing wall covering materials maybe Lquite expensive due to the fact that in many instances they must bewoven in the same manner as conventional carpeting, even though suchwall coverings are not required to withstand the abuse and trafic thatfloor carpeting is subjected to. Therefore, the heavier designed wallcoverings are often significantly more expensive than the relativelythin wall paper or the like.

Accordingly, it is a primary object of the present invention to providea method of making a nonwoven wall covering material which ischaracterized by the simultaneous looping of a large number of fibers,threads or the like, and the incorporation of the thus looped fibersinto a nonwoven fabric with the loops extending outwardly from thebacking layer, and which has a relatively thin barrier layer secured tothe backing layer to permit the use of any of a wide variety ofadhesives or adhesive means for securing the wall covering material to asurface, such as a wall, as Well as to add dimensional stability to thematerials, thereby producing a novel high-loft wall covering materialwith a pleasing surface texture and appearance.

A further object of the present invention is to provide a method ofmaking a nonwoven wall covering material that is economical as comparedto woven wall covering materials, but which may have the appearance ofsuch woven materials.

Still another object of the present invention is to provide a simple andhigh speed production method of making the high-loft nonwoven Wallcovering material from a web of fibers, threads or the like having anopen adhesive pattern previously printed on one side, by consolidatingthe adhesive into a backing while simultaneously looping the fibersoutwardly from the adhesive backing and subsequently applying a barrierlayer to the sheet, as well as a means for securing the material to asurface.

In one of its more specific aspects, it is an object of the invention toapply a specific barrier layer to the adhesive backing whereby theadhesive bond between the layer and adhesive backing is greater than thebond between the barrier layer and the surface to which the wallcovering material is applied.

Other objects and advantages of the present invention will become morereadily apparent upon reading the following detailed description andupon reference to the attached drawings, in which:

FIG. l is a schematic view, in side elevation, of one form of apparatuswhich may be employed to produce a high-loft, nonwoven fabric;

|FIG. 2 is a fragmentary plan view of an illustrative web of basematerial while still supported on a conveyor belt, somewhat simplifiedand exaggerated for the sake of clarity of illustration, with portionsbroken away to expose the various layers;

FIG. 3 is a fragmentary plan View of one embodiment of the product madeby the apparatus of FIG. l;

FIGS. 4 and 5, respectively, are greatly enlarged, simplified, andsomewhat exaggerated sectional views taken substantially along the lines4 4 and 5-5- in FIG. 3;

FIG. 6 is an enlarged schematic detail view, in side elevation, of theforming drum and gathering blade of the apparatus shown in FIG. 1;

FIG. 7 is an enlarged schematic side elevational View illustrating, inSomewhat idealized fashion, successive stages in the sequence ofgathering and looping of individual fibers;

(FIG. 8 is an enlarged schematic fragmentary View, taken substantiallyalong the line 8 8 of FIG. 7, here showing a fragment of the fiber weband adhesive pattern with illustrative fibers attached to the adhesive;

FIG. 9 is a simplified schematic View, taken substantially along theline 9-9 of FIG. 7, here Showing the fragment of the fiber web andadhesive pattern depicted in FIG. 8 at a later stage in the loop formingsequence;

FIG. 10 is a schematic view, in side elevation, of one form of apparatusthat may supplement the apparatus shown in FIG. 1, and is adapted toapply a second pattern of second adhesive to the first pattern fadhesive;

IFIG. ll is a fragmentary plan view of an illustrative web of basematerial having two applications of adhesive, the View being somewhatsimplified and exaggerated for the sake of clarity of illustration, withportions broken away to expose the various layers;

FIG. 12 is a greatly enlarged, simplified and somewhat exaggeratedsectional view taken substantially along the line 12-12 of FIG. ll;

FIG. 13 is a schematic view, in side elevation, of exemplary apparatuswhich may be employed to apply a barrier layer to the adhesive backingof the wall covering material, as Well as to apply a means for securingthe wall covering material to a surface;

FIG. 14 is a fragmentary view of the Wall covering material, greatlyenlarged and in cross section, illustrating the barrier layer securingthereto, and is taken along line 14-14 of FIG. 13;

FIG. 15 is a fragmentary View of the wall covering material, greatlyenlarged and in cross section, illustrating the wall covering materialhaving the barrier sheet as well as a securing means attached thereto,and is taken substantially along line 15-15 of FIG. 13;

FIGS. 16 through 19 illustrate, in plan view, exemplary alternativeadhesive patterns that may be used for the base web;

FIG. 20 is a plan view illustrating the wall covering material havingbeen cut in predetermined squares for subsequent application to asurface; and,

FIG. 21 is a plan view of the wall covering material having been cut ina number of pieces of a mosaic pattern for subsequent application to asurface.

While the invention is susceptible of various modifications andalternative forms, specific embodiments thereof have been shown by wayof example in the drawings and will herein be described in detail. Itshould be understood, however, that it is not intended to limit theinvention to the particular forms disclosed, but, on the contrary, theintention is to cover all modifications, equivalents and alternativesfalling within the spirit and scope of the invention as expressed in theappended claims.

THE ENVIRONMENT OF THE INVENTION To produce a high-loft nonwoven fabric,a base web of fibers is first prepared and an open adhesive pattern isapplied to one side of the web. Different procedures have been used inpreparing the base web. For example, textile length fibers may beprocessed through conventional cotton card machinery to produce a cardedweb for the base web. In such a carded web 50% to 70% of the fibers mayybe oriented substantially parallel with the machine direction. It hasbeen found, however, that the most uniform product has been obtainedwith the method of the present invention by using base webs having ahigher percentage of the fibers alined with the machine direction such,merely by way of example, as a highly drafted web in which, as a resultof the drafting process, to 95% of the fibers may be alined with themachine direction. Such webs of bonded, highly drafted fibers, ofcourse, have substantial utility in themselves and are the subject, forexample, of the aforesaid copending application, Ser. No. 79,287 andU.S. Pat. No. 3,553,065. The present invention, however, goes far beyondthe preparation of an adhesively bonded carded web or the products andmethods disclosed in those two applications, and results in theformation of a high-loft, nonwoven wall lcovering material havingsignificantly different characteristics than the nonwoven web utilizedas the base material.

Broadly stated, the method of the present invention involves taking thebase material and performing the subsequent steps of: (l) reactivatingthe open pattern of adhesive in which the fibers are embedded; and, (2)consolidating the adhesive into a backing layer, while (3)simultaneously looping the portions of the fibers across the open spacesof the adhesive outwardly from the backing layer formed by theconsolidated adhesive, (4) securing a barrier layer to the consolidatedadhesive backing, and (5) subsequently applying to the barrier layer ameans for securing the material to a surface, such as a wall.

A further method step of applying a second pattern of adhesive to thefirst pattern of adhesive may also be performed prior to thereactivation and consolidation steps. The second application of adhesivemay offer detinite advantages in the event heavy denier fibers, as wellas threads and yarns are used, all of which will be describdhereinafter.

The resulting product is characterized by the high loft or deep pile ofthe loops of fibers which extend outwardly from the adhesive backing.The particular depth of pile or degree of loft of the loops, of course,depends upon a combination of control parameters, including, forexample: the type and denier of the base fibers; and the amount of andspacing within the original adhesive pattern; the angle of the gatheringblade; and the relative speeds of fiber delivery to and fabric dischargefrom the gathering blade; as will be discussed hereinafter. The barrierlayer is adapted to improve the dimensional stability and tensilestrength of the wall covering material, as well as isolate the adhesivebacking layer so that any of various means for securing the material toa wall surface or the like may be used without concern that thestructural integrity of the adhesive system used to secure the materialto a surface will be impaired through physical or chemical reaction.

In addition, the present method also contemplates, in some instances,additional steps, such as: laminating a thin sheet of paper or the likehaving a permanent adhesive on one side for securing the sheet to thebarrier layer and an adhesive applied to the opposite side thereof forsecuring the Wall covering material to a wall or the like. The oppositeside may be covered by a suitable re 1 lease coated cover strip, toprotect the adhesive until immediately before applying the wall coveringmaterial to a surface.

By way of background, the basic method for producing a high-loftnonwoven fabric will now be described in detail. Turning now to thedrawings, FIG. l schematically illustrates an exemplary apparatus forproducing a highloft nonwoven fabric. This apparatus includes a webforming section and an adhesive compacting and fiber looping section 30.The web forming section 10 is generally similar to the apparatusdisclosed in the aforesaid copending application, Ser. No. 79,281, withcertain modifications as disclosed in the aforesaid U.S. Pat. No.3,553,065 but it is here shown in more complete and visible form thanshown in either of those disclosures. It will be appreciated as theensuing description proceeds, that fiber Webs made in accordance withthe method disclosed in the aforesaid copending application, Ser. No.79,281, are also usable with the subsequent method steps for producingthe hereinafter described fabric, as are carded webs and webs preparedby other processes.

As shown in FIG. l, multiple slivers 11 of textile fibers are drawn fromtheir respective supply cans (not shown) into a draw frame 12 whichcomprises a series of pairs of grooved rolls 13; the rolls of each pairbeing driven by appropriate gearing (not shown, but well known in theart) at a peripheral rate of speed somewhat faster than the rate ofoperation of the preceding pair. Merely by way of example, the pairs ofrolls 13 may be adjusted to provide an over-all increase in speed and,therefore, an extent of fiber draw on the order of :1 through the drawframe 12. As the juxtaposed slivers pass through draw frame 12, theindividual fibers are drafted and spread out to form a at, striated webof substantially alined fibers as shown at 14. Web 14 is maintainedadjacent a supporting conveyor sheet 15 on the surface of which adhesivehas been previously applied in a preselected pattern.

In this embodiment, the conveyor sheet 15 comprises an endless conveyorbelt treated on at least its upper surface with a release agent. Oneexample of such a belt comprises woven glass fiber with a surfacecoating of tetrafiuoroethylene resin. Other examples of release coatingsare well known, and comprise such materials as silicones, fatty acidmetal complexes, certain acrylic polymers, and the like. Heat resistantfilms or thin metal sheets treated with release agents may also be usedas the carrier sheet.

Prior to the time the web 14 is picked up by the belt 15, the latter hasimprinted on its release-treated surface a pattern of flexible,thermoplastic adhesive such as is shown at 16 in FIG. 2. It will beunderstood that, as shown in FIG. 1, the adhesive is actually on theunderside of belt 15 which becomes the upper surface after passingaround roll 17, at which time the adhesive pattern 16 directly contactsthe fiber web 14. The pattern is shown as being visible in FIG. 2 onlyfor illustrative purposes.

The belt 15 is fed around roll 17 at a speed slightly in excess of thedelivery speed of the final pair of rolls 13 of draw frame 12 in orderto maintain web 14 under a slight tension, whereby the individualhighly-drafted fibers are retained in their alined and tensionedcondition. Drive rolls 18, 19 are rotated (by suitable drive means, notshown) to drive belt 15 at a speed sufficient to maintain the propertension on the web 14.

In the method shown for applying adhesive, the belt 15 is fed through anip formed between a printing roll 20 and a back-up roll 21 maintainedin very light pressure engagement therewith. The surface of printingroll 20 is provided with an intaglio pattern to which adhesive may besupplied in various ways well known to those skilled in the art. Forexample, in the aforesaid parent application, Ser. No. 769,959, a systemis schematically disclosed wherein the lower portion of the printingroll 20 picks up adhesive directly from a dip pan, with excess adhesivebeing removed by a doctor blade, thus leaving only the intagliopatterned surface filled. However, it has been found that moresatisfactory results are obtained by pumping or otherwise transferringadhesive 22 from a supply pan 23 to a reservoir located immediatelyabove an inclined doctor blade 24the reservoir being defined in part bythe upper surface of the inclined doctor blade and the adjacent portionof the rotating peripheral surface of the printing roll 20. Thus, as theprinting roll 20 rotates (in a counterclockwise direction as viewed inFIG. 1), the intaglio patterned surface thereof is filled with adhesive22, excess adhesive is removed by the doctor blade 24, and a meteredamount of adhesive is then transferred to the underside of releasecoated belt 15 in a preselected pattern. The pattern shown in FIG. 2 isin the form of an open diamond pattern of adhesive.

The particular dimensions of the intaglio pattern employed and, indeed,the actual pattern itself, are not critical to the practice of theinvention in its broadcast aspects. Thus, it has been found thatpatterns other than the illustrative diamond pattern hereinabovereferred to can be utilized, and certain of such patterns will besubsequently described in connection with FIGS. 16-19. For illustrativepurposes, however, it is noted that excellent results have been achievedwhere a diamond pattern was employed in which adjacent lines of adhesivewere spaced apart in both directions by 1A, and wherein the intaglioprinting roll 20 had adhesive cells or lines 0.007 deep and 0.025" wide.In certain instances, however, it has been found that the dimensions ofthe adhesive cells or lines, together with their spacing, are criticaland must differ from the foregoing exemplary dimensions.

Since the surface of belt 15 is treated with a release coating, theadhesive remains substantially on the surface with no penetrationtherein and is preferably in a somewhat tacky condition. The printedbelt is drawn from the printing nip around roll 17 positioned closelyadjacent the output end of draw frame 12 and, as stated above, at aspeed slightly in excess of the delivery speed of the last two rolls inthe draw frame. The web 14 emerging from the draw frame 12 is depositedon the tacky adhesive 16 on belt 15 and held in tensioned engagementtherewith by the adhesive and the above-mentioned speed differential.This continuous tension prevents the fibers in the web from losing theirhighly-drafted and alined condition.

In practicing the method herein described, additional alined andhighly-drafted fibers may be added to the web 14 on the adhesivelyprinted belt 15. For this purpose, a second draw frame 25 similar to thedraw frame 12 is provided to draw additional slivers 26 of fibers fromtheir supply cans (not shown) and, after drafting and alining them, todeposit the fibers on the moving web 14 carried by the belt 15. In suchcases, the amount of adhesive printed on the belt 15 may be increased toinsure that some of' the adhesive in the adhesive pattern 16 penetratesthe fibrous web 14 drawn from the draw frame 12 and reaches the fibersdrawn from slivers 26 which pass through the second draw frame 25. Thearrangement is such that the adhesive contact between the fibers drawnfrom slivers 26 and the pattern 16, together with the speed differentialof the belt 15 relative to the last pair of rolls in the draw frame 25,maintain the fibers drawn from slivers 26 under slight tension, wherebythey also maintain their highly-drafted and alined condition.

The fibers deposited on the web 14 from draw frames 12 and 25 need notbe the same kind, size, color or quantity. Nor, for that matter, do thefibers of the slivers 11 and 26 need to be uniform in these respects asthey are drawn into the draw frames 12 and 25. Thus, various blends offiber sizes, kinds, colors and xquantities can be deposited across theweb 14 from each of the draw frames 12 and 25 and in variouscombinations of first and second layers of fibers. Additional drawframes can also be employed if desired.

The bers from each of the draw frames 12 and 25 pass under respectivebars 27 and 28 before being deposited on the belt 15. The bars 27, 28may be oscillated in a direction generally transverse to the movement ofthe web 14 and, preferably, provision is also made for controlling thefrequency and amplitude of the oscillation of one bar relative to theother. Thus, as each bar is oscillated, the bers deposited from therespective draw frames 12 and 25 take on a generally sinusoidal orsawtooth wave pattern of controlled frequency and amplitude. A simple,but somewhat similar, oscillating bar arrangement is disclosed in theaforesaid U.'S. Pat. No. 3,553,065. However, the single bar arrangementthere disclosed did not afford, nor even contemplate, the significantlyimproved attributes made possible by the present method.

An example of the web 14 formed on the illustrative apparatus (FIG. l)is shown in FIG. 2. As previously mentioned, a series of parallel anddiagonally disposed lines of adhesive are printed in criss-cross fashionon the belt 15 to form a pattern 16 of adhesive having substantiallyopen spaces in the configuration of diamonds. In depositing the fibersfrom the first draw frame 12, the bar 27 was not, in this instance,oscillated. Thus, the fibers making up the first component 14a of theweb 14 are substantially all alined in the direction of web movement.The fibers making up the second component 14h of the web, however, Willbe seen t0 be deposited in a generally wavy or saw-tooth pattern as aresult of oscillation of the bar 28 associated with the second drawframe 2S, thus altering the appearance characteristics of the finishedfabric. In addition, oscillation of the bars 27 and/or 28 serves toalter the structural and functional characteristics of the fabric inthat a controllable percentage of the bers may be deposited on the openadhesive pattern at an angle to the machine direction. It has been foundthat such fibers do not interfere to any significant extent with thesubsequent fiber looping steps. Moreover, it is believed that thepresence of such fibers extending at an angle to the machine directionserves to increase the cross-directional strength of the fabric beingproduced by actually increasing the number of oriented fibers whichextend partially in the fabric cross-direction. Preferably, when bothbars 27 and 28 are oscillated they are oscillated in out-of-phaserelation to one another so as to cause fibers in one web component 14ato cross fibers in the other web component 14!) at even greater angleswhile simultaneously maintaining the fibers in a highly oriented state.It will, of course, be understood that the phase and amplitude of theoscillated fiber pattern may be selectively adjusted and controlled toprovide a controlled angular deposition of fibers on the open adhesivepattern 16, thus enabling control of the cross-directional strengthcharacteristics of the fabrics resulting from fiber oscillation. Thiswill, of course, vary dependent upon various other parameters such, forexample, as the type of fibers employed, the type of adhesive employed,fiber-adhesive ratios, gathering ratios, and indeed, the particular enduse to which the fabric is to be put. Consequently, in many instances itmay not be desirable to oscillate either bar 27 or 28. It should beappreciated, of course, that FIG. 2 is only intended to be illustrativeand, while the lines representing the fibers for both components 14a and141: are spaced apart for clarity, in practice the highlydrafted fibersof both components are very close to one another.

Also for illustrative purposes, it will be noted that web component 14bhas three bands of fibers designated color. These bands of fibers may bethe same or different colors; but, in any event, they differ from thecolor of the ybalance of the fibers of web component 14h. Further, aspreviously mentioned, the fibers of web component 14b may differ fromthose of component 14./z in kind, size, color or quantity depending uponthe desired color pattern and surface characteristics of the finalproduct, as more specifically described below.

Following deposit of web components 14a and 14b on the adhesive printedbelt 15, the belt is drawn around a heated curing drum 29 where fusingand curing of the adhesive is substantially completed while the web 14is maintained in firm contact therewith to bond the individual fibers.To insure effective heating and fusing of the adhesive, it is desirablethat travel of the combined belt and web be around a substantial portionof the drum 29. In the illustrated embodiment, a -fly roll 29a ispositioned to apply tension on the combined belt and web as they travelaround the drum 29 to insure complete embedment of the .fibers in theadhesive. The fibers of the web 14 are thus bonded together whileretaining their highly-drafted and substantially alined condition in theparticular pattern in which they were deposited on the open pattern ofadhesive 16 printed on the belt 15.

After leaving the fiy roll 29a, the combined web 14 and belt 15 arepreferably passed over the drive roll 19, which also serves as a coolingdrum to set the adhesive. The bonded web 14 is stripped from therelease-coated surface of the belt 15 by the guide roll 31 as the webleaves the cooling drum 19.

While various Well-known adhesives may be employed in the foregoingprocess, advantages reside in the use of plastisols, which are colloidaldispersions of synthetic resins in a suitable organic ester plasticizer,and which, under the infiuence of heat, provide good binding power whileremaining soft and fiexible. While many adhesives of this type areknown, those found particularly useful for incorporation in the productof this invention include vinyl chloride polymers, and copolymers ofvinyl chloride with other vinyl resins, plasticized by organicphthalates, sebacates, or adipates. These provide a fast curingplastisol adhesive characterized by relatively low viscosity, lowmigration tendencies, and minimum volatility. Such adhesives remain softand iiexible after curing, and can be reactivated by subsequent heating.

It has been found that other adhesives may be employed in theprocess-for example, organisols utilizing resins such as the vinylchloride polymers and copolymers. Furthermore, still other adhesives maybe employed provided that they satisfy specified characteristics in thebase web produced in the web forming section 10, and in the finishedfabric produced in the adhesive compacting and fiber looping section 30(FIG. 1). In general, such adhesives should be applied to the base webby procedures which will not disarrange the fibrous structure of theweb; such adhesives should heat-set at temperatures below thedegradation temperature of the fibers in the base web 14 to securebonding of the fibers to the adhesive; such adhesives should bereactivatable in the subsequent adhesive gathering and consolidationstage of the process; and such adhesives should form a flexible backinglayer for the finished fabric and should strongly bond the fiber loopsin place. For example, emulsions of thermoplastic resins such asacrylics and rubber-like compounds, illustratively ABS, have therequisite properties to serve as the bonding adhesive for the web 14.

The base material, made as heretofore described and comprising a web 14of highly-drafted fibers embedded in an open adhesive pattern, is fedinto the adhesive consolidating and fiber looping section 30 of theapparatus shown in FIG. 1. As shown here, the web 14 continues directlyfrom the web forming section 10 to the consolidating and looping section30. It should be appreciated, however, that the web 14 discharged fromsection 10 could be rolled up for storage or transport and thensubsequently unrolled and fed into section 30. Also, as previouslymentioned, other webs such, merely by way of example, as those made inaccordance with the methods disclosed in the aforesaid copendingapplications, Ser. Nos. 498,929 and 553,483, can be further processed insection 30.

As illustrated in FIG. 1, the web 14, while still under tension, is fedaround an idler roll 32 and on to the surface of a heated forming drum37. In its preferred embodirnent, the drum 37 is made of metal with ahighly polished, chromium plated surface which is heated and maintainedat a temperature of approximately 250 F. Also, the web 14 is arranged totravel a substantial distance around the drum 37 with the open patternof adhesive 16 in contact with the heated drum surface. As the web 14 isfed onto the drum 37, the heat from the drum surface reactivates andsoftens the adhesive printed on the underside ofthe web, causing it tobe tacky and to adhere slightly to the drum surface, thereby maintainingthe web under constant tension. The drum temperature, which ismaintained at about 250 F., is, however, maintained below the meltingpoint of the adhesive to prevent dispersion of the adhesive into thefibers of the web.

The web 14 of fibers and softened adhesive is reformed by thecooperative action of the drum 37 and a gathering blade 38 having a flatedge 39. The blade edge 39 operates to consolidate the open adhesivepattern 16 into a substantially continuous backing layer of adhesive,while simultaneously looping the fibers of the web outwardly frombetween the open spaces in the original adhesive pattern. The reformedand consolidated material 40 then leaves the blade edge 39 and movesonto a flat take-off surface 41 and a discharge conveyor 52.

Turning now t FIGS. 7-9, the method of making the novel high-loft,nonwoven fabric 40 will be explained in greater detail in connectionwith an illustrative sequence of the gathering and looping of a singlefiber of the web 14 and the consolidation of its two original points ofadhesive attachment in the pattern 16. As seen in FIG. 8, the fiber hasa portion P which extends across the open space of the diamond patternof adhesive 16 from point A to point B where it is embedded in theadhesive. Referring to FIG. 7, the series of views in this figureillustrates how the portion P of the fiber is formed into a loop; viz.,when -point A being carried around the heated drum 37 impinges againstthe gathering blade edge 39, its forward motion is halted and it isscraped along the surface of the drum, while point B continues toadvance with the drum surface since, due to its softened and tackycondition, it adheres to the smooth drum surface. As point B advancesrelative to point A, the portion P of the fiber between points A and Bis caused to bow outwardly from the drum surface. Finally, point Bovertakes point A and these points of adhesive are substantiallyconsolidated as seen in FIG. 9. In the meantime, fiber portion P hasbeen looped outwardly from the drum surface.

It will, of course, be understood that while looping of ber portion P isoccurring, additional adhesive points C-D, etc., travelling around thedrum 37 impinge against the gathering blade edge 39 causing aconsolidation of these adhesive points and looping of their intermediatefiber portions P1 as is also indicated in FIG. 9. This occurssimultaneously at all points across the web at the blade edge, producinga substantially continuous backing layer of adhesive from which extendsthe multiplicity of loops formed by the fibers of the base web. The thusformed substantially consolidated layer of adhesive is carried away fromthe blade edge 39 along the take-off surface 41 and provides asubstantially continuous backing layer for the outwardly looped libers,thus producing the fabric 40.

While in the preferred form, it is desired to achieve substantiallycomplete consolidation of the adhesive into a continuous backing layer,in practice it has been found that the degree of consolidation variesrandomly throughout the substantially continuous backing and, therefore,it is possible to draw the fabric slightly, thus producing asubstantially continuous adhesive backing layer with random openingstherethrough. Since `complete consolidation, while desirable, is notnecessarily attained in practice the degree of consolidation is definedherein, and in the appended claims, in terms such as to consolidate theopen adhesive pattern into a substantially continuous adhesive layer.Thus, those skilled in the art will appreciate that terms such asconsolidate as used herein and in the appended claims are intended toconnote an arrangement for consolidating or compacting the open adhesivepattern into a substantially continuous adhesive backing layer--albeitthat such substantially continuous backing may have, and often willhave, small random fissures and gaps therein-all as distinguished fromthe arrangement disclosed in the aforesaid copending application, Ser.No. 820,224, wherein the open adhesive pattern is only partiallyconsolidated to minimize bonding of adjacent lines of adhesive and thusform a discontinuous adhesive backing layer characterized by itselasticity and/ or stretchability.

Another important feature is that not only does each fiber portion Ploop outwardly from the drum surface but, also, as the loop is formed itturns, reaching a position in the fabric 40 generally perpendicular tothe direction of the original alinement of liber portion P. Thus, theber loops arrange themselves so that the plane of each loop issubstantially normal to the original fiber alinement shown in FIG. 8.The reason for the loop twisting as it is formed may be explained bythis observation. If two spaced points of a single liber not in a webare brought together, it has been observed that the fiber will form aloop and, as the loop is formed, it twists towards a position of minimuminternal stress, turning through an angle which tends to approach lSO".In carrying out the method, because of the .great number of fibers inthe web and their proximity one to another, each fiber loop engages theneighboring liber loops with the result that all the loops are blockedfrom turning beyond the plane substantially normal to the machinedirection, and are constrained in that position by the inteferencebetween the loops. In practice, of course, the actual direction anddegree of loop twist depend upon the characteristics of the fibers inthe original web 14.

It is important to note, however, that throughout the fabric the heightsof the ber loops vary according to the spacing between the points ofattachment of each fiber to the open adhesive pattern in the base web.Referring to FIGS. 4, 8 and 9, it will be seen, for example, that theloop formed by the fiber portion P1 between the points of adhesiveattachment C, D will have a lower height than the loop formed by thelonger fiber portion P between the points A, B. On the other hand,however, successive loops in adjacent diamonds, when viewed in avertical section taken along the machine direction (FIG. 5 will have thesame height since the fiber length P will remain the same betweensuccessive sets of points A, B. This results in a dense fabric with thelower loops supporting and filling around the higher loops and the topsurface of the fabric being formed by the tops of the higher loops.

The appearance of a fabric so constructed depends not only on the heightof the fiber loops but, also, on the type and denier of the fiber usedin the base web, and one of the features of the invention is that thedepth of the fabric and the evenness of the surface may be varied byadjusting selected ones of the control parameters, as will be explainedbelow. In general, it may be said that for both relatively low andmoderate height high-loft materials which have been produced with themethod of this invention, the fabric appears to have a uniform thicknesswith a somewhat uneven surface texture. With very deep highloft fabrics,particularly those made from exible, low denier fibers, the higher loopstend to lay one over the other, thus providing a very soft, napped,fuzzy, fibrous surface.

To illustrate the effect of varying one of the control parameters, inthis case, the angle of the edge of the blade 38 relative to the drum 37will now be described. Referring to FIG. 6, it will be seen that theblade edge 39 forms an angle a with the line T tangent to the surface ofthe drum 37. It has been found that the blade edge angle a is oneparameter that determines the depth of the fabric produced and thedegree of uniformity of consolidation of the adhesive backing layer.

As a result of trying different blade angles, it has been determinedthat the preferred blade edge angle a when dealing with adhesivepatterns having lines of adhesives spaced approximately 1A apart isbetween about 17 and about 34. With blades having edge angles withinthis preferred range, fabrics have been produced which are characterizedby having a high degree of uniformity of consolidation of the adhesivebacking layer which is substantially void of fissures or gaps and, byhaving a dense, regular mass of loops that provide a textured, somewhatuneven surface.

With blades having edge angles a less than 17, difficulty has beenexperienced in obtaining a uniformly consolidated adhesive backinglayer. This appears to be the result of insufficient relief between theblade edge and the drum surface for the fabric to flow evenly andsmoothly off the drum surface as the result of the action of the blade,which produces varying degrees of consolidation of the adhesive and anon-uniform layer with fissures and gaps and scattered areas where thelooping is irregular, tending to spoil the surface appearance of thefabric. With blades having edge angles a substantially above 34, boththe problem of non-uniform adhesive consolidation and poor loopformation has been experienced. There is also a tendency as the angle aof the blade edge is increased substantially above 34 for the fabric tobe formed with pronounced ridges, which may be undesirable in thefinished product.

In practice, it has been found that one of the major factors effectingthe thickness of the fabric is the loop height as determined and limitedby the spacing between points of fiber adhesive attachment A-B, C-D,etc. (FIG. 8). To obtain the maximum thickness of fabric with a givenadhesive pattern, the blade edge angle a should be such as to producenot only sufficient consolidation of the adhesive layer to provide goodfiber attachment throughout the fabric but, also, sufficientconsolidation to insure the production of a maximum number of fullheight fiber loops. Thus, as the blade edge angle a increases, thecondition is approached where the web is being skived off the rollrather than being consolidated and gathered. The fabrics produced withthe higher blade edge angles a have reduced adhesive consolidation andfabric thickness because fewer loops reach their maximum height.

In using a blade 38 having an edge angle a within the preferred range,it has been found that the fabric loft may be regulated by changing themachine direction dimension of the adhesive pattern. Thus, by increasingthis dimension, the height of the loops may be increased, therebyincreasing the fabric loft. Larger diameter bers, strands, or yarns mayalso be used as the elements of the base web to produce heavier,carpet-like finished fabrics. The adhesive and its pattern ofapplication must, however, take into consideration the amount ofadhesive required to form the backing layer under the consolidatingaction of the gathering blade 38, and sufficient adhesive must bepresent to provide a substantially continuous backing layer ofsufficient thickness to obtain strong attachment of the loops in thefinished fabric. More specific disclosures of types of adhesive patternssuitable for use in making carpet-like fabrics of larger diameter bers,strands, or yarns may be found in the aforesaid copending application ofHerman G. Minshell, Robert J. Stumpf and William J. Mattes, Ser. No.77,840, which is assigned to the assignee of the present invention.

Now turning to a consideration of a different control parameter--viz,the location of the take-away surface 41-the preferred location of thetake-away surface is, as shown in the extreme right-hand view in FIG. 7,tight against the blade 38- and even with the outside corner 39' of theblade. With the surface 41 in this preferred location, the fabric mayhave a moderately even surface texture and a dense mass of loops forminga deep, highloft pile.

It has been found that by lowering the take-away surface 41 a distance Y(FIG. 7) from its preferred location, the structure of the fabric willbe drastically affected, in that the bulk of the fabric may be increasedsubstantially by lowering the take-away surface 41. The effect oflowering the surface is somewhat similar to the effect from using ablade 38 with an edge angle a substantially above the preferred range inthat pronounced ridges are also produced in the fabric, therebyincreasing its bullk. The amount that the take-away surface is lowereddoes clearly effect the degree of bulking, and it is apparently the casethat as the distance Y increases, the fabric bulk increases.

A further related parameter that affects the gathering function of theblade is the take-away speed of the fabric from the blade edge. Withblade 38 having an edge angle a within the preferred range, and atake-away surface at the preferred location, the take-away speed isdesirably regulated to remove the newly formed fabric at the rate atwhich it is being formed, and it has been found that under theseconditions the normal ratio of the surface speed of the heating drum 37to the take-away speed will be about 12:1. By increasing the ratio upto, for example, 15:1, by slowing down the fabric take-away speed, moreuniform adhesive consolidation has been obtained while the mass of thefiber loops is made somewhat rnore dense, so that a fabric with a higherWeight has been produced. By increasing the fabric take-away speed, suchthat the fabric is not allowed to gather at the blade edge 39, thefabric will be drawn or extended while the adhesive layer is still in aplastic condition, thereby opening the adhesive layer, thinning thefabric pile, and reducing the Weight of the nished material.

Thus, by selection of the blade edge angle a, take-away ratio, and theheight of the take-away surface 41, the fiber looping, fabric pleatingplus bulk and basis weight of the fabric may be controlled to produce aproduct of desired characteristics.

Further parameters that affect adhesive consolidation and fiber loopingat the blade edge 39 are: (l) the adhesive pattern applied to the fibersin the formation of the base web 10i; (2) the adhesive weight as apercentage of the weight of the web; (3) andthe area of the web coveredby the adhesive pattern.

In addition to the diamond pattern, other adhesive patterns which may beused include unevenly spaced lines of application, such as criss-crossedsine waves as shown in FIG. 16. The spacing of such lines of adhesivemay furthermore be increased or decreased to change the maximum heightof the element loops and, thus, the depth and surface texture of thefinished material.

When criss-crossed lines of adhesive are used, the loops of the fabricwill have varying heights due to the different spacings of the points ofattachment (A-B, C-D-FIG. 8) of the base web elements to the adhesive.To produce a fabric Iwith loops of uniform height, the adhesive isapplied to the base web 14 in lines evenly spaced apart and extendingacross the Web. Furthermore, the spacing between the lines of adhesivemay be increased or decreased to obtain a higher or a lower pile height,as desired. `Referring to PlIiG. 17, one such adhesive pattern isillustrated in the form of evenly spaced diagonal lines 82. Another suchadhesive pattern is illustrated in FIG. 18, in the form of lines 84,each in the shape of a sine wave. A brick-like pattern is another suchpattern as shown in FIG. 19. If broken lines of adhesive are utilized toobtain element looping-such, for example, as the brick-like pattern ofFIG. l9-the gaps in the lines of adhesive 86 should be staggered so thatthe web elements longitudinally span the spaces between the adhesivelines and are securely attached to the adhesive.

When the spacing of points of attachment of the bers to the adhesivevaries regularly over the area of the base web as, for example, when anopen diamond pattern of adhesive is used, the loops in the finishedfabric will vary in height in a regular manner to provide a uniformlyvarying surface having a textured appearance. When, on the other hand,an open pattern of adhesive is used in which, in the cross direction ofthe base web 14, the lines of adhesive are parallel, or evenly spaced,it will be seen that the spacing of points of attachment of the elementsto the adhesive will be uniform over the total area of the fabric, andthe loops in the finished fabric will be of uniform height to provide amore even surface. The appearance of such a surface will, of course, beaffected by the characteristics of the elements which form the loops.Thus, where the elements are yarn or heavy strands of fibers, the loopswill be clearly visible, while where the elements are small diameter,flexible fibers, the surface will have a fibrous appearance, the fiberlooping being less evident.

It has been observed that the transverse adhesive lines, whenconsolidated by the action of the gathering blade 338, are moved intoproximity or abutment with each other and, being in a soft tacky statedue to the high temperature of the heating drum 37, tend to bond to eachother. However, the bond between lines of adhesive may be broken and theopen pattern of adhesive substantially restored by drawing the fabric inthe machine direction after the adhesive backing layer has been cooled,all as more clearly described in the aforesaid copending applicationSer. No. 820,224. IIt may thus be demonstrated that the backing layer,while it appears to be continuous in the finished fabric, actuallycomprises lines of adhesive extending in the cross direction of thefabric and bonded to each other.

In the application of the adhesive to the base web, it has been observedthat by increasing the adhesive viscosity, a sharp, distinct printedpattern will be obtained such that the fibers are securely attached tothe adhesive at distinct spaced points and are not embedded in adhesivethroughout their length. It is desired to have spaced points of fiberadhesive attachment so that the fiber loops will be distinctly andseparately formed at the gathering :blade in such a manner as to extendoutwardly from the adhesive bonding layer. Fiber sizes between 1-1/2denier and l5 denier have been successively utilized in the base web 14and a 1A inch diamond pattern of adhesive. With higher denier fibers, orwith strands or yarns used in the prepa-ration of the base web, theadhesive pattern is preferably enlarged so as to insure attachment ofthe fibers or strands to the adhesive at spacings along the length ofthe threads or yarns which will define the depth of pile or degree ofloft in the finished material. With the light-weight webs of rayon theratio of fiber to adhesive is preferably approximately 1:1. It has beenfound that the degree of adhesive fiber attachment in the base web wasaffected when the fiber-to-adhesive ratio with such type fibers wassubstantially increased above 1:1, so that the fiber loops did not formproperly at the blade 38, nor did the rfibers have sufficient attachmentto the adhesive layer in the finished fabric. On the other hand,increasing the relative amount of the adhesive in the base web had theresult of producing a thicker adhesive layer in the finished materialand more secure liber attachment, but the adhesive lines tend todisperse so that the pattern becomes less open, thereby affecting theheight of the loops, which is undesirable. The fiber-adhesive ratio willbe different, however, for base webs of yarns and threads where itappears that less amounts of adhesive, relatively speaking, will provideadequate attachment of the loops to the adhesive backing layer.

While staple length rayon fibers may be used for the preparation of thefabrics, other fibers may also be used in the process in its preferredform, and have resulted in fabrics of excellent properties of hand,drape, and appearance.

For example, acrylic, olefin and polyester fibers have been used, and itis within the contemplation of the invention to use any of all of thesebers by themselves or in blends, as well as natural fibers, acetate,nylon and 14 other synthetic fibers in staple length or in monofilamentform, any of which may be used for the preparation of the base web 14.Moreover, not only highly drafted webs and carded webs of staple lengthfibers may be used for the base web, but, also, garneted and air-laidwebs of such fibers as well as directly laid alined webs ofmonofilament. It has been noted, however, that when webs such as cardedwebs are used for the base web in which an important proportion of thefibers are randomly oriented, those fibers not alined with the machinedirection appear to interfere with the loop production by the gatheringblade. The most regular formation of loops with the loops turned normalto the machinedirection has been produced with those base webs havingthe highest proportion of fibers alined with the machine direction as,for example, the highly drafted webs made with the apparatus illustratedschematically in FIG. 1.

It is also contemplated that flexible threads, yarns or strands may beused for forming a base web, provided that the flexibility of suchelements is high enough to permit looping of the fibers and turning ofthe loops in the manner heretofore described. To obtain regular loops ofsuch elements in the finished material, it is clear that substantiallyall such elements should be parallel and extend longitudinally of theweb, for loop formation will be interfered with by those elements thatsubstantially depart from such longitudinal alinement.

It has been found that in order to produce a material fully inaccordance with the present invention, the elements should besufiiciently flexible to allow the loops to form and to twist normal tothe machine direction while being formed under the action of theadhesive consolidating and gathering blade 38. Thus, neither stiffstrands, when used in this method, which do not loop under the action ofthe gathering blade 38, nor multiple strand yarns in which the lay ofthe strands opposes the tendency of the loops to twist while beingformed under the action of the blade, will satisfactorily serve aselements of the base web 14 when it is desired to produce a fabric fullyin accordance with the present invention.

It will, therefore, be seen that the features of the finished fabric aredetermined by the characteristics of the particular elements used in theformation of the base web 14 and, to some extent at least, by the natureof the process used in forming the base web.

Additional preliminary steps in the formation of the base web 14, aswell as subsequent steps for processing the fabric 40 after it flowsfrom the gathering blade 38, may be optionally carried out to alter thecharacteristics of the finished fabric.

Referring to FIG. 1, the base web 14, as has been previously described,may be formed of webs from two drafting frames 12, 15 supplied withstaple length fibers or monofilaments. Patterns of color or of fiberswhich differ from the main constituent of the fabric may be introducedinto the finished fabric 40 by utilizing certain preliminary steps inthe formation of the base webs.

For example, the underweb from the first drafting frame 12 may be madefrom fibers 0f a solid color while at spaced intervals across the baseweb 14a bands of one or more colors may be introduced by passing coloredfibers through the second draw frame 25 so that the colored fibers arelaid on the underweb 14a. The top layer 14b of fibers may be applied inthe pattern desired and, it has been found, will effectively screen outthe underweb color in most instances so that the finished material willdisplay a striped appearance.

The top layer 14b of fibers from the draw frame 25 may also beintroduced in wavy or saw-tooth pattern to produce either a wavy orsaw-tooth effect completely across the fabric, as illustrated in FIG. 2,or in bands across the fabric as desired.

Alternatively, the under layer 14a of the base web 14 may embodydifferent colored fibers by having the fibers at the margins, forexample, of one color While the fibers across the center of the web areof a different color or colors. To this end, different colored fibersmay be introduced through either or both draw frames 12 and/ or 25. Thetop layer of fibers may be in the form of spaced bands of fibers acrossthe web, or the different color may be introduced through only thesecond draw frame 25 by laying down a uniform layer of fibers in whichat least certain of the adjacent slivers are of different colors. Wherethe top layer of the base web comprises spaced bands of fibers, it willbe app-reciated that the finished fabric will have a varying weightacross the web, with a double weight and a more dense mass of loops inthe bands where the top bers are laid down.

`Other procedures may be used for introducing patterns into the finishedfabric. For example, a layer of fibers in the form of a section of a webfrom the second draw frame 25 may be laid on a web from the first drawframe 12 or onto a carded web underlayer. Due to the consolidationoperation performed by the gathering blade 38, the pattern will beshortened lengthwise but not appreciably disarranged laterally, suchthat whatever the pattern introduced into the layer of the base web 14,it will appear in the finished fabric in its fore-shortened form. Apattern of fibers may be introduced into the top draw frame 25, whichwill operate to aline the fibers and will draw or extend the pattern inthe machine direction. The subsequent shortening effect by the gatheringblade 38 will tend to reduce the pattern to its original form in thoseinstances where the extent of the draw in the drawing frame25-illustratively l5zl-is approximately the same as the take-away ratio.

As shown in FIG. 1, the fabric 40 is carried along the take-away surface41 by the action of the conveyor 52. Since the adhesive backing is hotand tacky as the fabric ows onto the take-away surface 41, that surfacemay be treated with a non-stick or release coating to insure that thefabric may be drawn smoothly along the surface.

To cool the belt of the conveyor 52 and prevent it from becomingoverheated from the hot adhesive back of the fabric 40, streams of airmay be blown against the underside of the belt from suitably placed airnozzles 54. This will also serve to cool the fabric 40, although it maybe necessary or desirable to pass the fabric through a cooling stationor zone (not shown) to cool the adhesive and thermoplastic fibers totemperatures below their softening temperatures or to eliminatetackiness of the adhesive.

The second printing of adhesive A further method step in the productionof a high-loft fabric is disclosed in copending application of HerbertG. Minshell, Robert I. IStumpf, and William I. Mattes, Ser. No. 77,840,and basically involves the application of a second adhesive pattern uponthe first applied open pattern of adhesive.

Referring to FIG. 10, an exemplary apparatus is shown for applying thesecond adhesive pattern to the base web, with the apparatus beingsuitably inserted between portions of the apparatus shown in FIG. 1after the web is passed over roller 31 and before it reaches the drum37. The exemplary apparatus 90 includes a first cooling station 92 forcooling the web and first adhesive pattern applied thereto, an adhesiveapplicator station 94 substantially similar to the adhesive applicationportion of the apparatus shown in FIG. 1, a curing roller 96 similar tothe roller 29, and a second cooling station 98 for cooling the web priorto its traveling to the drum 37. The printing roller of the adhesiveapplicator station 94 also has an intaglio patterned surfacesubstantially similar to the printing roll 20 shown in FIG. 1, so thatthe second adhesive pattern is applied to the first pattern of adhesive.In the event additional detailed information is desired concerning themethod of its application, reference is made to the above mentionedcopending application.

The double printing of adhesive on the fiber web may offer distinctadvantages in the resulting fabric, depending upon the particularfibers, threads, or the like that are being used. For example, assumingthe wall covering material is to be produced incorporating relativelyheavy denier fibers, as well as yarns, threads or the like that haveeither single or multiple threads, the double printing of adhesive inmany instances insures the secure attachment of the ends of the loopswithin the adhesive backing, but does not interfere with the proper loopformation during the consolidation stage ofthe method. As iscomprehensively described in the above copending application, thephysical thickness of a single pattern of adhesive may be increased onlyto a degree. Also, the adhesives being applied to the web may bedifferent with each of the different adhesives having characteristicscontributing to a better quality fabric. For example, the adhesiveapplied in the first pattern may be characteristically adapted toenhance the fiber holding or retaining capabilities, while the secondadhesive applied to the first pattern may have qualities whichcontribute to better consolidation during the adhesive consolidating andfiber looping step.

Thus, it is seen that for particular types of fibers, threads or thelike that are incorporated into the base web, the double printing ofadhesive step may be advantageously utilized.

Additional steps for producing the wall covering material In carryingout the method of the present invention, the high-loft, nonwoven fabricproduced during the consolidation step is subjected to additional methodsteps to yield the final wall covering material.

Referring to FIG. 13, the consolidated material 40 is conveyed by thetake-away conveyor 52 to a first laminating station indicatedl generallyat where a barrier layer is applied to the adhesive backing of theconsolidated fabric 40. Although the embodiment shown has the laminatingstation 100 as an in-line part of the apparatus of FIG. 1, it isappreciated that the consolidated fabric may be wound into a roll forshipment or storage and subsequently unwound by apparatus 102 shown inphantom, prior to applying the barrier layer thereto.

For laminating the barrier layer to the fabric 40, the laminatingstation 100 includes a calendar roll 103 which may have a hard rubbersurface, and a heated roll 104, which together form a nip for laminatingthe barrier layer 106 originating from supply roll 108. To insuresecurement of the barrier layer to the adhesive backing, a nip pressureis applied between the calendar and the heated roll. The heated roll 104is heated to a temperature of about 375 degrees to reactivate theconsolidated adhesive within the backing. Although a greater nippressure may be used, a pressure as low as 40 p.s.i.g. has been found toadequately secure the barrier layer when the heated roll is at thepreferred temperature.

Subsequent to application of the barrier layer, the web may then have ameans for securing the wall covering to a surface applied to the barrierlayer. Although many different adhesives or adhesive systems may beused, the embodiment illustrated in FIG. 13 has a nip formed betweenrollers 110 and 112 with an adhesive laminate 114 originating from roll116 being applied. Referring to FIG. 15, the adhesive laminate includesa thin sheet of paper or the like having adhesive applied to both sidesthereof. The outer adhesive will ultimately secure the wall covering toa wall or the like, and is preferably a pressure sensitive adhesive,although other adhesives may be used. The outer adhesive may also becovered with a release coated cover strip or the like, such as siliconetreated paper, `which will protect the adhesive until immediately beforeapplication to a wall or other surface, whereupon the cover strip ispeeled away.

There are of course other adhesive systems which may be used. Forexample, various adhesives in melt form may be directly applied to thebarrier layer and may or may not have a release coated strip protectingthe adhesive.

In accordance with another aspect of the present invention, the barrierlayer is preferably'a thin polyester film, and may have a thickness ofonly approximately -1/2 mil. The .polyester film may be Mylar asmanufactured by Du Pont of Wilmington, Del. Mylar is preferably used asthe barrier layer, for it is polar and thus exhibits good adhesion to avariety of surfaces and, in addition, it possesses sufficient thermalstability so that its structural integrity is not adversely affectedwhen the film is secured to the high-loft material by, for example,reactivating the plastisol backing. Other polymeric films having similarcharacteristics can also .be used, such as those prepared frompolyamides, acrylics and urethanes. In addition, films formed fromnormally polar .polymers such as olefns, e.g., polypropylene andpolyethylene, can also be used, though they ordinarily require anadhesion promotion surface treatment to be most effectively utilized.Moreover, such films ordinarily do not have great thermal stability and,thus, unless they are stabilized, such as by crosslinking, care must betaken in the manner by which they are secured to the high-loft material.

As previously mentioned, the barrier layer imparts greater tensilestrength as well as dimensional stability to the wall covering material,but in addition, acts as a barrier to prevent the plasticizer in theplastisol of the adhesive backing from leaching out of the backing. Theleaching of the plastisol may adversely affect the vbond between thewall covering material and the surface -to which it is ladhered becausethe plastisol may attack the adhesive system being used to secure thematerial to the surface. Thus, it is contemplated that in addition tothe use of the films previously mentioned, impregnated papers as well aschemical sprays may be formulated to adequately seal the plasticizer andtherefore prevent leaching.

In accordance with another aspect of the present invention, thepolyester film may also be corona discharge treated to improve itsdegree of adhesion. It is also noted that the corona discharge treatmentrenders the Mylar film more opaque and may therefore improve theappearance of the wall covering material to a purchaser, as theopaqueness at least partially covers the adhesive backing which may havean undesirable appearance. The corona discharge treatment simplyinvolves subjecting the surface of the film to a high potential electricdischarge.

In accordance with a further aspect of the present invention, the sideof the barrier layer receiving the corona discharge treatment is theside which receives the adhesive system for securing the wall coveringmaterial toa wall or the like. As previously mentioned, the coronadischarge treatment increases the Vadhesion capability of the barrierlayer. This coupled with the fact that the barrier layer is preferablyquite smooth, contributes to a stronger adhesive bond between theadhesive system and the barrier layer, as compared to the adhesivesystem and the surface to which the wall covering is applied. Therefore,with the wall covering material illustrated in FIG. 15, stripability ofthe Wall covering material is enhanced, in that the adhesive system willtend to remain secured to the barrier layer rather than the wall. Theadvantage is that cleaning or scraping of the wall for replacement ofwall covering or painting or the like is minimized.

The wall covering material may subsequently be cut into convenientlysized lengths of material that may be wound into rolls similar tocommonly marketed wall paper rolls, or may be cut into smaller segments,such as the squares 120 shown in FIG. 20 for individual application to awall surface. The advantage of such precut segments is that a designeror user may select various colored or designed segments and attach themto a wall or the like to suit his own taste. Of course, the precutsegments need not be limited to a square configuration, but may be cutinto other interconnecting designs, such as the mosaic pattern 122illustrated in FIG. 2l.

Thus, it is seen that the material of the present invention may offerunique advantages in terms of cost relative to conventional wofven wallcoverings.

Although the material is particularly suited for use as a wall covering,it is not exclusively limited to such use, and may be used to covertables and other furniture, room partitions, and other items suitablefor covering. It is also contemplated that the material may be used forcarpeting.

What is claimed is:

1. A fiexible nonwoven material comprising a laminate having:

a first layer comprising a high-loft nonwoven fabric comprising asubstantially continuous backing of exible adhesive formed by an openpattern of spaced apart adhesive bands extending in -the cross directionof the fabric which pattern has been consolidated in the machinedirection so as to bond said bands to each other to form a substantiallycontinuous, nonuniform backing, and a multiplicity of fibersindividually looped outwardly from the backing, with the ends of eachloop embedded in the backing, the v loops lying in substantiallyparallel planes; and,

second layer of flexible Ibarrier material adhesively secured to theadhesive backing of the first layer, said material providing a barrierto prevent leaching of the adhesive backing.

2. The material of claim 1 wherein the spacing of the points at whichthe ends of the loops are embedded in the adhesive backing variesregularly for fibers throughout the fabric layer so that the loops varyin height regularly throughout the fabric layer.

3. The material of claim 1 wherein the second layer is relatively thinpolymeric film.

4. The material of claim 3 wherein the polymeric film is selected fromthose consisting of polyesters, polyamides, acrylics, urethanes andpolyolefins.

5. The material of claim 3 wherein at least one side of the polymericfilm is corona discharged treated.

6. A flexible nonwoven material as defined in claim 1 wherein saidlbarrier material comprises a flexible sheet which providesreinforcement for the nonwoven material.

7. A flexible nonwoven material as defined in claim 1 including a meansassociated with the second layer for securing the material to a surface.

v 8. The material of claim 7 wherein the means for securing the materialto a surface is an adhesive.

9. The wall covering material of claim 1 wherein the adhesive backing inthe first layer is comprised of first and second plies of adhesiveadhering to each other.

10. The material of claim 7 wherein the means for securing the materialtothe surface comprises a sheet having adhesives applied to first andsecond sides thereof, with the first side being attachable to thebarrier layer and the second side being adapted to adhere the materialto the surface.

11. The material of claim 10 wherein a removable release treated coverlayer is applied to the second side for protecting the adhesive thereonprior to applying the material to the surface.

12. The material of claim 10 wherein one of the adhesives applied to thesheet is a pressure sensitive adhesive.

13. A fiexible nonwoven material comprising a laminate comprising: afirst layer comprising a high-loft, nonwoven fabric having asubstantially continuous backing of adhesive formed by an open patternof spaced apart adhesive bands extending generally in the crossdirection of the fabric which has been consolidated in the machinedirection so as to bond said bands to each other to form a substantiallycontinuous, nonuniform backing, and a multiplicity of fibersindividually looped outwardly from the backing, with the ends of eachloop embedded in the backing; a second layer of fiexible, adhesiveimpervious plastic sheet material, said sheet material providingreinforcement for the nonwoven material, while providing a barrier toprevent leaching of the adhesive backing and a generally smooth surfaceadapted to receive a thin layer of adhesive for securing the nonwovenmaterial to a surface.

14. A method for producing a nonwoven material having an outer surfacecomprised of a multiplicity of outwardly looped elements, the methodcomprising the steps of:

preparing a web including exible elements extending longitudinally ofthe web;

bonding the elements in an open pattern of adhesive;

reactivating the adhesive to a tacky state;

consolidating the open pattern of tacky adhesive at a consolidatingstation (i) to form a backing layer (ii) while looping the elementportions located in the open spaces of the adhesive pattern into thebacking layer; conveying the consolidated backing layer and outwardlylooped elements away from the consolidating station; and,

laminating a flexible barrier layer to the backing layer to provide abarrier to prevent leaching of the adhesive backing layer.

15. The method of claim 14 wherein the elements of the web are staplelength fibers.

16. The method of claim 14 wherein the web elements are selected fromthe group consisting of synthetic yarns, natural yarns, syntheticthreads, natural threads, or blends thereof.

17. The method of claim 14 wherein the open pattern of tacky adhesive issubstantially fully consolidated to form a substantially continuousadhesive backing layer.

18. The method of claim 14 wherein the barrier layer is a relativelythin polyester film.

19. The method of claim 18 wherein the polyester lm is corona dischargetreated on at least one side thereof.

20. The method as dened in claim 14 including the step of applying ameans for securing the wall covering material to a surface.

21. The method of claim 20 wherein the adhesive means is a coating ofadhesive.

22. The method of claim 14 wherein the open pattern comprises a seriesof interconnected diamonds.

23. The method of claim 14 wherein:

reactivation of the adhesive to a tacky state is achieved by carryingthe web onto a heated surface, and

consolidation of the open pattern is achieved by impinging the elementsand the tacky adhesive against the edge of a relatively moving gatheringblade.

24. The method of claim 14 wherein a second open pattern of secondadhesive is applied to the tirst applied open pattern of adhesive, thesecond pattern being substantially similar to the first applied patternand in general registry therewith, the second pattern of adhesive beingapplied sequently of bonding the elements in the rst applied pattern ofadhesive.

25. The method of claim 24 wherein the elements are bonded in the secondpattern of applied adhesive.

26. The method of claim 14 wherein the material is cut into pieces of apredetermined size and shape for individual application to the surface.

27. The method of claim 26 wherein the shape of the individual pieces issquare.

28. The method of claim 26 wherein the shape of the individual piecesdenes an interconnecting mosaic pattern.

29. The method of claim 26 wherein the shape of the pieces isrectangular and the size of the pieces is such that they are adapted tobe wound into a roll.

30. A method for producing a nonwoven material having an outer surfacecomprised of a multiplicity of outwardly looped elements, the methodcomprising the steps of:

preparing a web including exible elements extending longitudinally ofthe web;

bonding the elements in an open pattern of adhesive;

reactivating the adhesive to a tacky state;

consolidating the open pattern of tacky adhesive at a consolidatingstation (i) to form a backing layer (ii) while looping the elementportions located in the open spaces of the adhesive pattern into thebacking layer; Y conveying the consolidated backing layer and outwardlylooped elements away from the consolidating station; and,

reactivating at least the outer surface portion of said backing layerand laminating a flexible barrier layer to the backing layer to bondsaid barrier layer and said backing layer together.

References Cited UNITED STATES PATENTS 2,787,571 4/ 1957 Miller 161-633,271,216 9/1966 Koller 156--72 3,533,871 10/1970 Zentmyer 156-2053,214,323 10/ 1965 IRussell et al. 161--148 3,220,056 11/1965 Walton18-19 3,236,718 2/ 1966 Cohn et al. 161-128 ROBERT F. BURN ETT, PrimaryExaminer R. O. LINKER, J R., Assistant Examiner U.S. Cl. X.R.

